Slang originating from southern Iowa meaning to jump someone with one or more accomplices and then kicking or smushing your foot onto their mouth/teeth as hard as possible as the other person(s) holds them down.
Person 1: Bro, did you hear about Jack and Haley graining Josh yesterday?
Person 2: Yeah, I heard he won't be able to speak normally ever again, dude.
Person 2: Yeah, I heard he won't be able to speak normally ever again, dude.
by explosion95 January 21, 2023
Get the grainmug.